.TH expm1 3 "" "" ""
.SH SYNOPSIS
expm1, expm1f \- exponential minus 1
.SH ANSI_SYNOPSIS
#include <math.h>
.br
double expm1(double 
.IR x );
.br
float expm1f(float 
.IR x );
.br
.SH TRAD_SYNOPSIS
#include <math.h>
.br
double expm1(
.IR x );
.br
double 
.IR x ;
.br

float expm1f(
.IR x );
.br
float 
.IR x ;
.br
.SH DESCRIPTION
.BR expm1 
and 
.BR expm1f 
calculate the exponential of 
.IR x 
and subtract 1, that is,
@ifinfo
e raised to the power 
.IR x 
minus 1 (where e
@end ifinfo
@tex
$e^x - 1$ (where $e$
@end tex
is the base of the natural system of logarithms, approximately
2.71828). The result is accurate even for small values of
.IR x ,
where using 
.BR exp(<[x )-1>>
would lose many
significant digits.
.SH RETURNS
e raised to the power 
.IR x ,
minus 1.
.SH PORTABILITY
Neither 
.BR expm1 
nor 
.BR expm1f 
is required by ANSI C or by
the System V Interface Definition (Issue 2).
.SH SOURCE
src/newlib/libm/common/s_expm1.c
